import java.util.logging.Logger;

public class CalculationAreaExt extends CalculationArea
{
  final static double π = 3.141592653D;
  Logger logger = Logger.getLogger(CalculationAreaExt.class.toString());

  @Override
  public double circular(double r) 
  {
    this.logger.info("计算半径为：" + r + " 的面积");
    return (π * r * r);
  }
}
